Hatchback/liftgate Support Device problems of the 2003 Mitsubishi Eclipse

I have a Mitsubishi Eclipse 2003 gts. I purchased it in September 2002 and it only has 7,000 miles on it, so it is fairly new. There is a latch by the front seat to open the trunk. Ever since I had the car, the trunk never opens on the first try. Usually I have to pull the latch twice. Reason being is the trunk is so heavy with the spoiler on it, it doesn't want to pop up. There is no handle or any way to open the trunk what so ever. So a couple of days ago as my friend was lifting up on the trunk with the spoiler, the spoiler literally came off!!! there is no reason why on a brand new car the spoiler should just come off. So I took my car to the Mitsubishi dealership where I bought it and they said that I used excessive force. In order to pull a spoiler off you would think that one would literally have to stand on the bumper and yank for about 10 minutes. But my friend simply lifted up on it and it came off (considering there is no where else to lift up on the trunk). After my unsuccessful attempt at the Mitsubishi dealership I phoned Mitsubishi to file a compliant. After speaking to two people, the representative was not helpful what so ever and pretty much told me it was my fault because I should not use the spoiler as a handle. My friend barely even used any force! since the spoiler had to be completely taken off to drive it, now the trunk just pops up when the latch is pulled in the front by the seat. That just shows that the reason why it doesn't pop up with the spoiler is because it's too heavy! my compliant is now I have to pay $430. 00 for something that should be covered under warranty and isn't because they said excessive force was used. That is not true. Mitsubishi is not about making it right. It should be covered under warranty. There is no reason or excuse for a spoiler coming off that easy on a brand new car. That's basically telling me that a) it a piece of junk or b) it was not assembled right. I hope it's b and not a.